While this is possible, it is far from simple. Divider tabs are easier.
This number would be in a textbox or Frame in the header for each chapter. To have them positioned differently would require a different section for each Chapter. You would have to set the headers for each chapter to not be linked to previous.
- Sidebars and Marginal Text Using Frames https://addbalance.com/word/frames_textboxes.htm#sidebars
- Headers and Footers Recap https://www.addbalance.com/usersguide/sections2007.htm#Recap_of_Header/Footer_settings
- Link to Previous https://www.addbalance.com/usersguide/sections2007.htm#LinkPrevious
This document, once you do this, will be a pain to edit. Do it when you have your chapters organized the way you want them in the final document. Count on this taking a fair amount of time.